﻿using System;
using System.Collections.Generic;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Web;


namespace Infrastructures
{
    public class DataUtil
    {
        public static string SHA512Encrypt(string val)
        {
            SHA512 sha512 = new SHA512CryptoServiceProvider();
            return Convert.ToBase64String(sha512.ComputeHash(Encoding.UTF8.GetBytes(val)));
        }

        public static string SHA384Encrypt(string val)
        {
            SHA384 sha384 = new SHA384CryptoServiceProvider();
            return Convert.ToBase64String(sha384.ComputeHash(Encoding.UTF8.GetBytes(val)));
        }

        public static string RSAEncrypt(string val)
        {
            RSACryptoServiceProvider rsaToEncrypt = new RSACryptoServiceProvider();
            rsaToEncrypt.FromXmlString(SystemConfig.Get("PubKey"));
            byte[] byEncrypted = rsaToEncrypt.Encrypt(Encoding.UTF8.GetBytes(val), false);

            return Convert.ToBase64String(byEncrypted);
        }

        public static string RSADecrypt(string val)
        {
            RSACryptoServiceProvider rsaToDecrypt = new RSACryptoServiceProvider();
            rsaToDecrypt.FromXmlString(SystemConfig.Get("PriKey"));
            byte[] byDecrypted = rsaToDecrypt.Decrypt(Convert.FromBase64String(val), false);

            return Encoding.UTF8.GetString(byDecrypted);
        }

        public static string DESEncrypt(string val)
        {
            if (string.IsNullOrEmpty(val))
                return string.Empty;

            var returnValue = new StringBuilder();
            var des = new DESCryptoServiceProvider();
            byte[] inputByteArray = Encoding.Default.GetBytes(val);

            des.Key = Encoding.ASCII.GetBytes(SystemConfig.Get("DESKey"));
            des.IV = Encoding.ASCII.GetBytes(SystemConfig.Get("DESIV"));
            var ms = new MemoryStream();
            var cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            foreach (byte b in ms.ToArray())
            {
                returnValue.AppendFormat("{0:X2}", b);
            }
            return returnValue.ToString();
        }

        public static string DESDecrypt(string val)
        {
            if (string.IsNullOrEmpty(val))
                return string.Empty;

            // 定义DES加密对象
            var des = new DESCryptoServiceProvider();
            int len = val.Length / 2;
            var inputByteArray = new byte[len];
            int x, i;
            for (x = 0; x < len; x++)
            {
                i = Convert.ToInt32(val.Substring(x * 2, 2), 16);
                inputByteArray[x] = (byte)i;
            }

            // 通过两次哈希密码设置对称算法的初始化向量   
            des.Key = Encoding.ASCII.GetBytes(SystemConfig.Get("DESKey"));
            // 通过两次哈希密码设置算法的机密密钥   
            des.IV = Encoding.ASCII.GetBytes(SystemConfig.Get("DESIV"));

            var ms = new MemoryStream();
            // 定义加密流
            var cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            return Encoding.Default.GetString(ms.ToArray());
        }

        public class ValidateCode
        {
            public ValidateCode()
            {
            }
            /// <summary>
            /// 验证码的最大长度
            /// </summary>
            public int MaxLength
            {
                get { return 10; }
            }
            /// <summary>
            /// 验证码的最小长度
            /// </summary>
            public int MinLength
            {
                get { return 1; }
            }
            /// <summary>
            /// 生成验证码
            /// </summary>
            /// <param name="length">指定验证码的长度</param>
            /// <returns></returns>
            public string CreateValidateCode(int length)
            {
                int[] randMembers = new int[length];
                int[] validateNums = new int[length];
                string validateNumberStr = "";
                //生成起始序列值
                int seekSeek = unchecked((int)DateTime.Now.Ticks);
                Random seekRand = new Random(seekSeek);
                int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);
                int[] seeks = new int[length];
                for (int i = 0; i < length; i++)
                {
                    beginSeek += 10000;
                    seeks[i] = beginSeek;
                }
                //生成随机数字
                for (int i = 0; i < length; i++)
                {
                    Random rand = new Random(seeks[i]);
                    int pownum = 1 * (int)Math.Pow(10, length);
                    randMembers[i] = rand.Next(pownum, Int32.MaxValue);
                }
                //抽取随机数字
                for (int i = 0; i < length; i++)
                {
                    string numStr = randMembers[i].ToString();
                    int numLength = numStr.Length;
                    Random rand = new Random();
                    int numPosition = rand.Next(0, numLength - 1);
                    validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));
                }
                //生成验证码
                for (int i = 0; i < length; i++)
                {
                    validateNumberStr += validateNums[i].ToString();
                }
                return validateNumberStr;
            }
            /// <summary>
            /// 创建验证码的图片
            /// </summary>
            /// <param name="containsPage">要输出到的page对象</param>
            /// <param name="validateNum">验证码</param>
            public byte[] CreateValidateGraphic(string validateCode)
            {
                Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);
                Graphics g = Graphics.FromImage(image);
                try
                {
                    //生成随机生成器
                    Random random = new Random();
                    //清空图片背景色
                    g.Clear(Color.White);
                    //画图片的干扰线
                    for (int i = 0; i < 25; i++)
                    {
                        int x1 = random.Next(image.Width);
                        int x2 = random.Next(image.Width);
                        int y1 = random.Next(image.Height);
                        int y2 = random.Next(image.Height);
                        g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
                    }
                    Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic));
                    LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
                     Color.Blue, Color.DarkRed, 1.2f, true);
                    g.DrawString(validateCode, font, brush, 3, 2);
                    //画图片的前景干扰点
                    for (int i = 0; i < 100; i++)
                    {
                        int x = random.Next(image.Width);
                        int y = random.Next(image.Height);
                        image.SetPixel(x, y, Color.FromArgb(random.Next()));
                    }
                    //画图片的边框线
                    g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
                    //保存图片数据
                    MemoryStream stream = new MemoryStream();
                    image.Save(stream, ImageFormat.Jpeg);
                    //输出图片流
                    return stream.ToArray();
                }
                finally
                {
                    g.Dispose();
                    image.Dispose();
                }
            }
            /// <summary>
            /// 得到验证码图片的长度
            /// </summary>
            /// <param name="validateNumLength">验证码的长度</param>
            /// <returns></returns>
            public static int GetImageWidth(int validateNumLength)
            {
                return (int)(validateNumLength * 12.0);
            }
            /// <summary>
            /// 得到验证码的高度
            /// </summary>
            /// <returns></returns>
            public static double GetImageHeight()
            {
                return 22.5;
            }
        }
    }

}
